TWI577904B - Driving device - Google Patents

Description

Drive unit

The present application claims priority based on Japanese Patent Application No. 2011-235929, filed on Oct. 27, 2011. The entire contents of the application are incorporated by reference in this specification.

The present application relates to a drive device having a gear unit and an axial gap motor.

A conventional drive member includes an input shaft supported by a support member and a driven member engaged with the input shaft. An example of such a drive device is disclosed in International Publication No. WO 2009/081793. International Publication No. WO 2009/081793 is referred to as Patent Document 1 in the following description. The driving device of Patent Document 1 uses a thin flat motor to drive the input shaft.

The technique of Patent Document 1 is to drive an input shaft using a radial gap motor. It is difficult for a thin radial gap motor to obtain large torque. Therefore, when a thin motor is used, it is preferable to use an axial gap motor. However, an attractive force is generated between the rotor and the stator of the axial gap motor, thus affecting the axial direction force of the input shaft. If an external force that shifts the direction of the input shaft axis is applied to the input shaft, the smooth rotation of the input shaft is hindered. This specification provides a new construction drive that does not interfere with the smooth rotation of the input shaft over a drive having an axial clearance motor.

The driving device disclosed in the present specification includes a gear unit And an axial gap motor. The gear unit has an input shaft and a driven member. The input shaft is supported by a support member. The input shaft is engaged with the driven member. In this drive, two axial gap motors face and are mounted to the input shaft. With this drive, the attractive forces generated by the two axial gap motors are balanced with each other, so that the input shaft rotates smoothly.

The technique disclosed in the present specification, on a drive device having an axial gap motor, can realize a drive device such that external forces acting on the input shaft are balanced with each other in the axial direction.

Hereinafter, several technical features disclosed in the present specification are described. Moreover, each of the following matters has technical usefulness alone.

In the driving device disclosed in the present specification, the input shaft may be both sides extending from the driven member to the axial direction of the driven member. Then, the axial gap motors can be respectively disposed at both ends of the input shaft. The attraction of the motor acts against each other at both ends of the input shaft. Therefore, the input shaft can be rotated more smoothly.

In the drive device disclosed in the present specification, the plurality of input shafts may be disposed at equal intervals in the circumferential direction of the support member. In this case, the two axial gap motors may be faced and mounted only to one of the plurality of input shafts. Alternatively, two axial gap motors may be mounted on each of the plurality of input shafts, and each of the input shafts may be mounted in such a manner that two axial gap motors face each other. In any case, the action of the driven member can be stabilized. In the latter case, a large torque can be transmitted to the drive member.

(Example)

In the following embodiments, a gear transmission will be described in which A plurality of crank shafts are engaged to the external gears, and an axial gap motor is mounted to each of the crankshafts. The technique disclosed in the present specification can also be applied to a plurality of crankshafts that are engaged to internal gears, and an axial gap motor is mounted to the gear transmissions of the respective crankshafts. Further, it is also applicable to a gear transmission in which a plurality of crankshafts are engaged to an external gear or an internal gear, and an axial gap motor is mounted to one of the plurality of crankshafts.

In addition, the technology disclosed in the present specification can also be applied to a gear transmission in which one crankshaft is engaged to an external gear. That is, it should be noted that the technology disclosed in the present specification can be applied to various types of driving devices if the driving device is driven by an axial gap motor to drive the input shaft. Further, one of the internal gear and the external gear is eccentrically rotated, and the gear transmission along the other is called a cycloid reducer.

In the following embodiments, a gear transmission is illustrated in the form of a crankshaft offset from the axis of the carrier. However, the techniques disclosed in the specification are also applicable to a gear transmission in which the crankshaft and the carrier axis are coaxial.

(First embodiment)

The drive device 100 shown in FIG. 1 includes a gear unit 7 and two axial gap motors 22, 52. The gear unit 7 is a gear transmission in which the external gear 26 meshes with the internal gear 28 while being eccentrically rotated. The gear unit 7 has two external gears 26. In the gear unit 7, the carrier 8 rotates in accordance with the difference in the number of teeth of the external gear 26 and the internal gear 28. The internal gear 28 is composed of a casing 2 and an internal pin 30, and the internal gear pin 30 is disposed on the inner circumference of the casing 2.

The gear unit 7 includes a housing 2, a carrier 8, a crank shaft 32, and an external gear 26. The carrier 8 corresponds to a support member, the crankshaft 32 corresponds to an input shaft, and the external gear 26 corresponds to a driven member. The carrier 8 includes a first flat plate 8a and a second flat plate 8c. The gap exists between the first flat plate 8a and the second flat plate 8c. The columnar portion 8b extends from the first flat plate 8a toward the second flat plate 8c. The columnar portion 8b and the second flat plate 8c are fixed. The columnar portion 8b passes through the through hole 60 of the external gear 26. The external gear 26 is disposed between the first flat plate 8a and the second flat plate 8c. The carrier 8 coaxially supports the outer casing 2 by a pair of angular ball bearings 4. The axis 54 corresponds to the axis of the carrier 8. The axis 54 also corresponds to the axis of the internal gear 28 (outer casing 2).

The oil seal 6 is disposed between the outer casing 2 and the carrier 8. The first motor housing 50 and the second motor housing 20 are fixed to both ends of the carrier 8 in the direction of the axis 54. The through hole is formed in the center of the carrier 8 , the first motor cover 50 , and the second motor cover 20 . A cylindrical shaft 56 is fitted into the through hole. As a result, the drive unit 100 has a through hole 12 along the axis 54.

The crankshaft 32 is supported by the carrier 8 by a pair of bearings 23. The bearing 23 is a tapered roller bearing. The crankshaft 32 is located at an offset position from the axis 54 and extends parallel to the axis 54. The crankshaft 32 has two eccentric bodies 24. The two eccentric bodies 24 respectively engage the external gear 26. The two eccentric bodies 24 are eccentric with respect to the axis 35 of the crankshaft 32 in opposite directions. The crankshaft 32 extends from both sides of the eccentric body 24 in the direction of the axis 35. In other words, the crankshaft 32 extends from the outer gear 26 to both sides of the outer gear 26 in the axial direction.

The first axial gap motor 52 and the second axial gap motor 22 are attached to both ends of the crankshaft 32. Also, an encoder 18 is mounted on the song One end of the arbor 32. In the direction of the axis 35, the through hole is formed in the outer side of the second motor cover 20 on the outer side of the encoder 18, and the cover 19 is attached to the through hole.

The first axial gap motor 52 and the second axial gap motor 22 are disposed to face each other. The phase angle of the first axial gap motor 52 coincides with the phase angle of the second axial gap motor 22. Therefore, the crankshaft 32 is smoothly rotated. The gear unit 7 has three crankshafts 32, which will be described in detail later. The three crank shafts 32 are disposed at equal intervals in the circumferential direction of the carrier 8.

The first axial gap motor 52 and the second axial gap motor 22 are attached to each of the three crankshafts 32. The phase angles of the axial gap motors 52, 22 mounted to the three crankshafts 32 are completely identical. Since the phase angles of all the axial gap motors are the same, all the axial gap motors can be controlled by only one motor driver (not shown). The encoder 18 is mounted to one of the three crankshafts 32. The other two crankshafts 32 are attached with a brake (not shown).

The first axial gap motor 52 is composed of a first rotor 44 and a first stator 46. The first rotor 44 is attached to the crankshaft 32. As shown in Fig. 2, each of the three crankshafts 32 is mounted with a first rotor 44. The three crankshafts 32 are equally spaced around the axis 54. Similarly, the three first rotors 44 are also disposed at equal intervals around the axis 54. The permanent magnet 44N and the permanent magnet 44S are alternately disposed in each of the first rotors 44. The permanent magnet 44N is fixed to the surface of the brake 44a, and the N pole faces outward (see also FIG. 1). The permanent magnet 44S is fixed to the surface of the brake 44a, and the S pole faces outward. On all of the first rotors 44, the first rotor 44 is relative to the crankshaft 32 The angles are all equal. In other words, the positions of the N pole and the S pole with respect to the crankshaft 32 are equal in all of the first rotors 44. The crankshaft 32 and the first rotor 44 are combined by a spline having a plurality of grooves.

As shown in Fig. 3, the three first stators 46 are attached to the first motor cover 50. The three first stators 46 are disposed at equal intervals around the axis 54. The center of each of the individual first stators 46 is the same as the axis 35 of the individual crankshafts 32 (see also FIG. 1). The first stator 46 has a winding 46U through which a U-phase current flows, a winding 46V through which a V-phase current flows, and a winding 46W through which a W-phase current flows. The winding wire 46U and the winding wire 46V are wound into a stator core 46a by a winding wire 46W. The stator core 46a is formed of a powder magnetic core. The angles of the first stator 46 with respect to the first motor cover 50 are equal in all of the first stators 46. In other words, in all of the first stators 46, the winding wire 46U and the winding wire 46V are equal in the mounting position (rotation angle) of the winding wire 46W with respect to the axis 35 of the crankshaft 32. The stator core 46 is fixed to the first motor cover 50 by an adhesive, and the first stator 46 is attached to the first motor cover 50. Further, the winding wires 46U, 46V are shown in Fig. 1, and the winding wire 46W is not presented.

As shown in FIG. 1, the second axial gap motor 22 is composed of a second rotor 14 and a second stator 16. The second rotor 14 has a permanent magnet 14N whose N pole faces outward and a permanent magnet 14S whose S pole faces outward. The permanent magnets 14N, 14S are fixed to the surface of the flat plate 14a. The second stator 16 has a winding 16U through which a U-phase current flows, a winding 16V through which a V-phase current flows, and a winding 16W through which a W-phase current flows. The winding wire 16U and the winding wire 16V are wound into a stator core 16a by a winding wire 16W. The winding wires 16U, 16V are presented in Figure 1, and the winding wire 16W is not presented.

The structure of the second axial gap motor 22 and the first axial gap motor 52 are substantially the same. Therefore, a detailed description of the second axial gap motor 22 will be omitted. Further, when the axial gap motors 22 and 52 are viewed from the direction of the axis 35, the permanent magnet 14N and the permanent magnet 44N are arranged to overlap each other. Similarly, the winding wire 16U and the winding wire 46U are arranged in an overlapping manner, and the winding wire 16V and the winding wire 46V are arranged in an overlapping manner, and the winding wire 16W is overlapped with the winding wire 46W.

If the crankshaft 32 rotates, the eccentric body 24 will eccentrically rotate about the axis 35. The outer gear 26 rotates eccentrically around the axis 54 while the inner gear 28 meshes while being eccentrically rotated by the eccentric body 24. The number of teeth of the outer gear 26 and the inner gear 28 (the number of the inner tooth pins 30) is different. Therefore, if the external gear 26 is eccentrically rotated, the carrier 8 will rotate relative to the internal gear 28 (outer casing 2) corresponding to the difference in the number of teeth of the external gear 26 and the internal gear 28.

The features of the drive device 100 will be described. In the following description, the features common to the first axial gap motor 52 and the second axial gap motor 22 will be described only for the first axial gap motor 52, and the description of the second axial gap motor 22 will be omitted. As described above, the first rotor 44 is fixed to the crankshaft 32, and the first stator 46 is fixed to the first motor cover 50. The first motor cover 50 is detachable from the carrier 8 that supports the crankshaft 32. Therefore, the work of fixing the first rotor 44 to the crankshaft 32 and fixing the first stator 46 to the motor cover 50 can be performed individually. The crankshaft 32 is supported by the carrier 8, so that the first rotor 44 can be said to be positioned relative to the carrier 8.

In brief, the features of the drive device 100 (the carrier 8) and the components (the first motor cover 50) on which the first stator 46 is attached can be replaced with other detachable components. The first rotor 44 borrows Positioned by mounting on the carrier 8. The first stator 46 is positioned by being attached to the first motor cover 50. The positioning operation of the carrier 8 by the first rotor 44 and the positioning operation of the motor cover 50 by the first stator 46 can be easily performed. When the motor cover 50 is attached to the carrier 8, the phase angles of the first rotor 44 with respect to the first stator 46 are synchronized in all of the first axial gap motors 52.

For example, when both the rotor and the stator are to be positioned against the carrier, the stator must be fixed to the carrier while synchronizing the phase angle of the stator with respect to the rotor. Such work is difficult. Therefore, it is common to temporarily fix the rotor to the crankshaft, and in this state, fix the stator to the carrier. Next, the rotor is fixed to the crankshaft in a state where the current flows to synchronize the phase angles of the rotors. The technique disclosed in the present specification enables the present technology to manufacture the driving device in a simple manner by replacing the rotor-mounted component and the stator-mounted component with other detachable components.

Other features of the drive device 100 will be described. As described above, the first axial gap motor 52 and the second axial gap motor 22 are disposed to face each other. In the case of an axial gap motor, the attractive force acts between the rotor and the stator. If only one axial gap motor is attached to the crankshaft 32, a force in the direction of the axis 35 acts on the crankshaft 32. By placing the two axial gap motors 52, 22 facing each other on the crankshaft 32, the attractive forces of the two axial gap motors 52, 22 cancel each other out. Specifically, the urging forces of the two axial gap motors 52, 22 are reversely applied to the crankshaft 32 at both ends of the crankshaft 32. The balance of the force applied to the crankshaft 32 becomes better, causing the crankshaft 32 to smoothly rotate.

First axial gap motor 52 and second axial gap motor 22 are arranged At both ends of the crankshaft 32. In other words, the first axial gap motor 52 is provided on the other side of the second axial gap motor 22 with respect to the external gear 26 . More specifically, the axial gap motors 52 and 22 are fixed to the crankshaft 32 on the outer side of the pair of bearings 23 (tapered roller bearings) in the direction of the axis 35. The first rotor 44 (second rotor 14) can be fixed to the crankshaft 32 in a state where the crankshaft 32 supports the carrier 8.

Further, by fixing the axial gap motors 52 and 22 to both ends of the crankshaft 32, the first stator 46 and the second stator 16 can be positioned at both ends of the axis 35. By arranging the axial gap motors 52 and 22 at both ends of the crankshaft 32, the first rotor 44 (second rotor 14) can be opposed to the first stator 46 by the first motor cover 50 and the second motor cover. The phase angles of the (second stator 16) are simply synchronized.

The position of the first axial gap motor 52 and the position of the second axial gap motor 22 can be expressed as follows. The first axial gap motor 52 is disposed at one end of the crankshaft 32, and the second axial gap motor 22 is disposed at the other end of the crankshaft 32. The first rotor 44 and the second rotor 14 are disposed between the first stator 46 and the second stator 16 . The external gear 26 is disposed between the first rotor 44 and the second rotor 14. The first rotor 44 is disposed on the opposite side of the second stator 16 with respect to the second rotor 14 . The first stator 46 is disposed on the opposite side of the second rotor 14 with respect to the first rotor 44.

(Second embodiment)

A drive device (gear transmission device) 200 will be described with reference to Fig. 4 . The drive device 200 is a modification of the drive device 100. The same components as the drive device 200 and the drive device 100 will be denoted by the same symbols or The last two digits are the same symbol, and thus the description thereof is omitted.

In the drive device 200, the first axial gap motor 52 and the second axial gap motor 22 are fixed to the same side of the crankshaft 32 with respect to the external gear 26. More specifically, the first axial gap motor 52 is disposed at one end of the crankshaft 32. Further, the second axial gap motor 22 is disposed between the external gear 26 and the first axial gap motor 52. The brake 217 is attached to the other end of the crankshaft 32. The drive unit 200 also has three crankshafts 32. The brake 217 is attached to two of the three crankshafts 32. The encoder (not shown) is attached to the other crankshaft 32.

In the drive device 200, as described above, two axial gap motors are disposed at one end of the crankshaft 32 in the direction of the axis 35. As a result, a space for attaching the large outer diameter brake 217 to the other end of the crankshaft 32 can be secured. Further, even in the drive device 200, the first axial gap motor 52 and the second axial gap motor 22 face each other. The attractive forces of the two axial gap motors 52, 22 act against the crankshaft 32 in opposite directions. The attractive forces of the first axial gap motor 52 and the second axial gap motor 22 cancel each other out. Therefore, the crank shaft 32 can be smoothly rotated.

In the drive device 200, the first rotor 44 and the second rotor 14 are integrated. More specifically, the permanent magnets 44N and 44S are fixed to the surface (opposing surface) of one side of the flat plate 34. The permanent magnets 44N and 44S form the first rotor 44 by the flat plate 34, and the permanent magnets 14N and 14S form the second rotor 14 by the flat plate 34. That is, the first rotor 44 and the second rotor 14 are shared by the flat plate 34.

In the driving device 200, the first stator 46 is fixed to the outer edge of the first motor 250, and the second stator 16 is fixed to the carrier 208. When the first motor outer periphery 250 is fixed to the carrier 208, the winding 46U of the first stator 46, the winding 16U of the second stator 16, the winding 46V of the first stator 46, and the winding 16V of the second stator 16 Each of the winding wire 46W (not shown) of the stator 46 and the winding wire 16W (not shown) of the second stator 16 is fixed to the carrier 208 so as to face each other.

The points of attention regarding the embodiments will be described. In order to fix the stator core to the outer edge of the motor, a curable resin, a bolt, or the like may be used instead of the adhesive. Alternatively, the stator core and the outer edge of the motor may be integrally formed by using a resin.

In the first and second embodiments, the rotors of the two axial gap motors face each other on the respective crankshafts. It is also possible that the stators of the two axial gap motors face each other. That is, two stators may be disposed between the two rotors.

The embodiments of the present invention have been described in detail above, but are not intended to limit the scope of the claims. The description of the patent application includes various changes and modifications to the specific examples described above. The technical elements exemplified in the present specification or the drawings are technically useful by themselves or in various combinations, but are not limited to the combinations described in the claims at the time of filing. Moreover, the techniques exemplified in the specification or the drawings simultaneously achieve a plurality of purposes, and maintain technical usefulness by achieving one of the objectives themselves.

2‧‧‧ Shell

4‧‧‧Bevel ball bearings

6‧‧‧ oil seal

7‧‧‧ Gear unit

8‧‧‧ Carrier

8a‧‧‧1st tablet

8b‧‧‧ Column

8c‧‧‧2nd tablet

12‧‧‧through holes

14‧‧‧2nd rotor

14a‧‧‧ tablet

14N, 14S‧‧‧ permanent magnet

16‧‧‧2nd stator

16a‧‧‧Silker core

16U, 16V‧‧‧ coil

18‧‧‧Encoder

19‧‧‧ cover

20‧‧‧2nd motor cover

22‧‧‧2nd axial gap motor

23‧‧‧ Bearing

24‧‧‧Eccentric body

26‧‧‧Internal gear

28‧‧‧External gear

30‧‧‧ internal gear

32‧‧‧ crankshaft

35‧‧‧ axis

44‧‧‧1st rotor

44a‧‧‧Brake

44N, 44S‧‧‧ permanent magnet

46‧‧‧1st stator

46a‧‧‧Silker core

46U, 46V, 46W‧‧‧ coil

50‧‧‧1st motor cover

52‧‧‧2nd axial gap motor

54‧‧‧ axis

56‧‧‧Cylinder shaft

60‧‧‧through holes

100‧‧‧ drive

200‧‧‧ drive

208‧‧‧Vector

208a‧‧‧1st tablet

208b‧‧‧ Column

208c‧‧‧2nd tablet

250‧‧‧1st motor rim

Fig. 1 is a cross-sectional view showing a driving device of a first embodiment.

2 is a view showing the driving device of the first embodiment, the outer cover is supported by the supporting member Plan view of the gear unit in the removed state.

Fig. 3 is a plan view showing the outer cover of the driving device of the first embodiment, which is removed by the supporting member.

Fig. 4 is a cross-sectional view showing the driving device of the second embodiment.

2‧‧‧ Shell

4‧‧‧Bevel ball bearings

6‧‧‧ oil seal

7‧‧‧ Gear unit

8‧‧‧ Carrier

8a‧‧‧1st tablet

8b‧‧‧ Column

8c‧‧‧2nd tablet

12‧‧‧through holes

14‧‧‧2nd rotor

14a‧‧‧ tablet

14N, 14S‧‧‧ permanent magnet

16‧‧‧2nd stator

16a‧‧‧Silker core

16U, 16V‧‧‧ coil

18‧‧‧Encoder

19‧‧‧ cover

20‧‧‧2nd motor cover

22‧‧‧2nd axial gap motor

23‧‧‧ Bearing

24‧‧‧Eccentric body

26‧‧‧Internal gear

28‧‧‧External gear

30‧‧‧ internal pin (pin)

32‧‧‧ crankshaft

35‧‧‧ axis

44‧‧‧1st rotor

44a‧‧‧Brake

44N, 44S‧‧‧ permanent magnet

46‧‧‧1st stator

46a‧‧‧Silker core

46U, 46V‧‧‧ coil

50‧‧‧1st motor cover

52‧‧‧1st axial gap motor

54‧‧‧ axis

56‧‧‧Cylinder shaft

60‧‧‧through holes

100‧‧‧ drive

Claims (3)

A driving device comprising: a gear unit comprising: an input shaft supported by a support member; and a driven member engaged with the input shaft; and at least two axial gap motors, wherein the input shaft is from The position at which the driven member is engaged extends to both sides of the axial direction of the driven member, wherein the two axial gap motors face each other and are mounted to one end of the input shaft, and the brake is attached to the input shaft. One end. The driving device according to claim 1, wherein the plurality of input shafts are plural. The driving device of claim 2, wherein two of the aforementioned axial gap motors are mounted on each of the input shafts, and each of the aforementioned inputs is mounted in such a manner that two of the axial gap motors face each other On the shaft.